Mitochondrial plasticity in response to changing abiotic factors in Antarctic fish and cephalopods

368 Pages·2013·12.36 MB·English

Mitochondrial plasticity
in response to changing abiotic factors
in Antarctic fish and cephalopods
Anneli Strobel
The cover page contains artwork by Odra Noel (www.odranoel.eu)
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Mitochondrial plasticity in response to changing abiotic factors in Antarctic
fish and cephalopods

Mitochondriale Anpassungsfähigkeiten Antarktischer Fische und
Cephalopoden unter sich ändernden Umweltbedingungen

Dissertation
zur Erlangung des akademischen Grades
– Dr. rer. nat. –

dem Fachbereich 2 Biologie/ Chemie
der Universität Bremen
vorgelegt von

Anneli Strobel
Diplom-Biologin

Bremen, Februar 2013
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Gutachter:

1. Gutachter: Prof. Dr. Hans O. Pörtner
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
Am Handelshafen 12, 27570 Bremerhaven

2. Gutachter: Prof. Dr. Guy Claireaux
Institut Universitaire Européen de la Mer
Unité PFOM, Centre Ifremer de Brest, 29280 Plouzane, France
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CONTENT
Table of Contents

Summary V
Zusammenfassung IX
List of abbreviations XIII
List of figures XV

1 Introduction __________________________________________________ 1

1.1 The Southern Ocean 1
1.2 Physiological adaptations of life in the Southern Ocean 2
1.2.1 Organismic level 2
1.2.2 Mitochondrial function and cold adaptation 4
1.3 Ocean warming 9
1.4 Ocean acidification 9
1.5 Physiological impacts of warming and hypercapnia 10
1.5.1 Organismic level 10
1.5.2 Mitochondrial level 13
1.6 Cephalopods vs. Fish: convergences and limitations 15
1.7 Aim and outline of the thesis 17

2 Material and Methods _________________________________________ 21

2.1 Experimental Animals 21
2.2 Acclimation setup 26
2.2.1 Fish 26
2.2.2 Cephalopods 27
2.3 Whole animal oxygen consumption 28
2.4 Sampling and acid-base parameters 29
2.5 Heart fibre and mitochondrial isolation 31
2.5.1 Heart fibre preparation 31
2.5.2 Mitochondrial isolation 33
2.6 Substrate - inhibitor protocol 34
2.7 Enzyme assays 36
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CONTENT
2.8 Lipid extraction 36
2.9 Statistics 37

3 Publications _________________________________________________ 39

Publication I 43
Mitochondrial acclimation capacities to ocean warming and acidification are limited
in the Antarctic nototheniid fish, Notothenia rossii and Lepidonotothen squamifrons
Publication II 79
Metabolic shifts in the Antarctic fish Notothenia rossii in response to rising
temperature and PCO
2
Publication III 97
Elevated temperature and PCO shift metabolic pathways in differentially oxidative
2
tissues of Notothenia rossii
Publication IV 131
Compensation capacities for ocean acidification in the Austral nototheniid N.
angustata
Publication V 159
Metabolic capacities in relation to temperature and hypercapnia in cephalopods from
various climate zones

4 Discussion _________________________________________________ 195

4.1 Metabolic responses of the Antarctic fish, Notothenia rossii 196
4.1.1 Mitochondrial capacities of warm- and hypercapnia-acclimated N. rossii 197
4.1.1.1 Chronic warm exposure of N. rossii 197
4.1.1.2 Chronic hypercapnia exposure of N. rossii 199
4.1.2 Comparison of tissues of different metabolic function 200
4.1.3 The mechanisms behind hypercapnia compensation 205
4.1.4 Systemic level 208
4.2 Comparison of mitochondrial capacities and thermal sensitivities in various
notothenioids 210
4.2.1 Thermal sensitivities in notothenioids originating from different
environments 210
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CONTENT
4.2.2 Hypercapnia sensitivities in N. rossii and N. angustata 217
4.3 Fish vs. cephalopods 218

5 Synopsis ___________________________________________________ 223

6 Future perspectives __________________________________________ 229

7 References _________________________________________________ 233

8 Appendix __________________________________________________ 247

8.1 Substrate-inhibitor protocols applied in mitochondrial respiration experiments 249

Publication AI 251
Mitochondrial Function in Antarctic Nototheniids with ND6 Translocation
Publication AII 265
Impact of Climate Change on Fishes in Complex Antarctic Ecosystems

Danksagung 343

Erklärung gem. § 6 (5) PromO 345

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